A focus in the hearing aid industry is to make hearing aids smaller and more discrete for the benefit of the user and thus a design which can decrease the size of the hearing aid is of importance. Further, it is of great interest from a cost perspective that designs are easy and cheap to manufacture. Generally a button battery is used in a hearing device and traditionally a battery door of a hearing aid has been fitted with a locking mechanism, e.g. operated by a small slider or relying on a spring effect of the material, leading to bulky hearing devices a complex manufacturing process and/or high failure rate of the locking mechanism.